Riser Coupling Rating 1
The load capacity ratings listed in Table 1 provide a means of general classification of coupling models based on stress magnitude caused by applied load. To qualify for a particular classification, neither calculated nor measured stresses in a coupling may exceed the allowable stress limits of the coupling material when subjected to the design load. The allowable material stresses are established in Section 3.8. Different sizes of the same coupling are to be rated independently. Riser...
Riser Coupling Testing 1
In addition to the stress distribution verification test prescribed in Section 3.6 above, three types of full-scale design qualification tests are recommended a load rating test to establish classification of the particular coupling design, a makeup test to demonstrate the ability of the coupling to be correctly made up in the field and the repeatability of proper make-up, and an internal pressure test to check pressure integrity and seal effectiveness. Optional performance tests may also be...
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RP 2R Design, Rating-, and Testing of Marine Drilling Riser Couplings require analysis of a 30 sector one-twelfth . The axial loading on such a 30 sector can be considered to be that caused by the design tension, uniformly distributed around the pipe. Determination of the equivalent load for bending is discussed in Section 3.7. The use of finite element analysis permits determination of stresses in complex structures, but accuracy of the analysis is very sensitive to the skill of the analyst....
Nomenclature
The following technical terms which pertain to the description of marine drilling riser couplings generally are defined for clarity. A comprehensive list of definitions pertaining to marine drilling riser systems is contained in RP2Q. Marine Drilling Riser A tubular conduit serving as an extension of the well bore from the equipment on the wellhead at the seafloor to a floating drilling rig. Coupling A mechanical means for joining two sections of riser pipe in end-to-end engagement. Riser Box...
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Buoyancy Buoyancy devices or floatation added to the riser joints to reduce their submerged weight. Coupling design types include, but are not limited to, the following Breech-Block Coupling A coupling which is engaged by partial rotation of one member into an interlock with another. Collet-Type Coupling A coupling having a slotted cylindrical element joining mating coupling members. Dog-Type Coupling A coupling having dogs which act as wedges mechanically driven between the box and pin for...
Riser Coupling Design 1
The marine riser coupling is in the primary load path of the riser and must be designed to the same loads as the riser pipe. Procedures for determination of those loads are described in API RP 2Q. Riser couplings should also be designed to facilitate use, maintenance and inspection. Guidelines for care and operation are given in API RP 2K. Because of its large slenderness ratio L r , a drilling riser's ability to resist environmental loading depends primarily on tension. The environment...
Figure Combined Net Section And Local Bending Stress Linear Interaction Curve
RP 2R Design, Rating, and Testing of Marine Drilling Riser Couplings crx, tryi crz normal stress in the direction of the indicated subscript rxy, txz, ry2 shear stress in the plane of the indicated subscripts The combined stress, uc, should not exceed the maximum allowable stress, such that, The net section and local bending stresses are not output directly by typical finite element computer programs, but can be readily derived from the stress output that is provided. The stress output provided...